xref: /freebsd/stand/lua/config.lua (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1--
2-- SPDX-License-Identifier: BSD-2-Clause
3--
4-- Copyright (c) 2015 Pedro Souza <pedrosouza@freebsd.org>
5-- Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
6-- All rights reserved.
7--
8-- Redistribution and use in source and binary forms, with or without
9-- modification, are permitted provided that the following conditions
10-- are met:
11-- 1. Redistributions of source code must retain the above copyright
12--    notice, this list of conditions and the following disclaimer.
13-- 2. Redistributions in binary form must reproduce the above copyright
14--    notice, this list of conditions and the following disclaimer in the
15--    documentation and/or other materials provided with the distribution.
16--
17-- THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20-- ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25-- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26-- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27-- SUCH DAMAGE.
28--
29
30local hook = require("hook")
31
32local config = {}
33local modules = {}
34local carousel_choices = {}
35-- Which variables we changed
36local env_changed = {}
37-- Values to restore env to (nil to unset)
38local env_restore = {}
39
40local MSG_FAILDIR = "Failed to load conf dir '%s': not a directory"
41local MSG_FAILEXEC = "Failed to exec '%s'"
42local MSG_FAILSETENV = "Failed to '%s' with value: %s"
43local MSG_FAILOPENCFG = "Failed to open config: '%s'"
44local MSG_FAILREADCFG = "Failed to read config: '%s'"
45local MSG_FAILPARSECFG = "Failed to parse config: '%s'"
46local MSG_FAILEXECLUA = "Failed to execute lua conf '%s': '%s'"
47local MSG_FAILPARSEVAR = "Failed to parse variable '%s': %s"
48local MSG_FAILEXBEF = "Failed to execute '%s' before loading '%s'"
49local MSG_FAILEXAF = "Failed to execute '%s' after loading '%s'"
50local MSG_MALFORMED = "Malformed line (%d):\n\t'%s'"
51local MSG_DEFAULTKERNFAIL = "No kernel set, failed to load from module_path"
52local MSG_KERNFAIL = "Failed to load kernel '%s'"
53local MSG_XENKERNFAIL = "Failed to load Xen kernel '%s'"
54local MSG_XENKERNLOADING = "Loading Xen kernel..."
55local MSG_KERNLOADING = "Loading kernel..."
56local MSG_MODLOADING = "Loading configured modules..."
57local MSG_MODBLACKLIST = "Not loading blacklisted module '%s'"
58
59local MSG_FAILSYN_QUOTE = "Stray quote at position '%d'"
60local MSG_FAILSYN_EOLESC = "Stray escape at end of line"
61local MSG_FAILSYN_EOLVAR = "Unescaped $ at end of line"
62local MSG_FAILSYN_BADVAR = "Malformed variable expression at position '%d'"
63
64-- MODULEEXPR should more or less allow the exact same set of characters as the
65-- env_var entries in the pattern table.  This is perhaps a good target for a
66-- little refactoring.
67local MODULEEXPR = '([%w%d-_.]+)'
68local QVALEXPR = '"(.*)"'
69local QVALREPL = QVALEXPR:gsub('%%', '%%%%')
70local WORDEXPR = "([-%w%d][-%w%d_.]*)"
71local WORDREPL = WORDEXPR:gsub('%%', '%%%%')
72
73-- Entries that should never make it into the environment; each one should have
74-- a documented reason for its existence, and these should all be implementation
75-- details of the config module.
76local loader_env_restricted_table = {
77	-- loader_conf_files should be considered write-only, and consumers
78	-- should not rely on any particular value; it's a loader implementation
79	-- detail.  Moreover, it's not a particularly useful variable to have in
80	-- the kenv.  Save the overhead, let it get fetched other ways.
81	loader_conf_files = true,
82}
83
84local function restoreEnv()
85	-- Examine changed environment variables
86	for k, v in pairs(env_changed) do
87		local restore_value = env_restore[k]
88		if restore_value == nil then
89			-- This one doesn't need restored for some reason
90			goto continue
91		end
92		local current_value = loader.getenv(k)
93		if current_value ~= v then
94			-- This was overwritten by some action taken on the menu
95			-- most likely; we'll leave it be.
96			goto continue
97		end
98		restore_value = restore_value.value
99		if restore_value ~= nil then
100			loader.setenv(k, restore_value)
101		else
102			loader.unsetenv(k)
103		end
104		::continue::
105	end
106
107	env_changed = {}
108	env_restore = {}
109end
110
111-- XXX This getEnv/setEnv should likely be exported at some point.  We can save
112-- the call back into loader.getenv for any variable that's been set or
113-- overridden by any loader.conf using this implementation with little overhead
114-- since we're already tracking the values.
115local function getEnv(key)
116	if loader_env_restricted_table[key] ~= nil or
117	    env_changed[key] ~= nil then
118		return env_changed[key]
119	end
120
121	return loader.getenv(key)
122end
123
124local function setEnv(key, value)
125	env_changed[key] = value
126
127	if loader_env_restricted_table[key] ~= nil then
128		return 0
129	end
130
131	-- Track the original value for this if we haven't already
132	if env_restore[key] == nil then
133		env_restore[key] = {value = loader.getenv(key)}
134	end
135
136	return loader.setenv(key, value)
137end
138
139-- name here is one of 'name', 'type', flags', 'before', 'after', or 'error.'
140-- These are set from lines in loader.conf(5): ${key}_${name}="${value}" where
141-- ${key} is a module name.
142local function setKey(key, name, value)
143	if modules[key] == nil then
144		modules[key] = {}
145	end
146	modules[key][name] = value
147end
148
149-- Escapes the named value for use as a literal in a replacement pattern.
150-- e.g. dhcp.host-name gets turned into dhcp%.host%-name to remove the special
151-- meaning.
152local function escapeName(name)
153	return name:gsub("([%p])", "%%%1")
154end
155
156local function processEnvVar(value)
157	local pval, vlen = '', #value
158	local nextpos, vdelim, vinit = 1
159	local vpat
160	for i = 1, vlen do
161		if i < nextpos then
162			goto nextc
163		end
164
165		local c = value:sub(i, i)
166		if c == '\\' then
167			if i == vlen then
168				return nil, MSG_FAILSYN_EOLESC
169			end
170			nextpos = i + 2
171			pval = pval .. value:sub(i + 1, i + 1)
172		elseif c == '"' then
173			return nil, MSG_FAILSYN_QUOTE:format(i)
174		elseif c == "$" then
175			if i == vlen then
176				return nil, MSG_FAILSYN_EOLVAR
177			else
178				if value:sub(i + 1, i + 1) == "{" then
179					-- Skip ${
180					vinit = i + 2
181					vdelim = '}'
182					vpat = "^([^}]+)}"
183				else
184					-- Skip the $
185					vinit = i + 1
186					vdelim = nil
187					vpat = "^([%w][-%w%d_.]*)"
188				end
189
190				local name = value:match(vpat, vinit)
191				if not name then
192					return nil, MSG_FAILSYN_BADVAR:format(i)
193				else
194					nextpos = vinit + #name
195					if vdelim then
196						nextpos = nextpos + 1
197					end
198
199					local repl = loader.getenv(name) or ""
200					pval = pval .. repl
201				end
202			end
203		else
204			pval = pval .. c
205		end
206		::nextc::
207	end
208
209	return pval
210end
211
212local function checkPattern(line, pattern)
213	local function _realCheck(_line, _pattern)
214		return _line:match(_pattern)
215	end
216
217	if pattern:find('$VALUE') then
218		local k, v, c
219		k, v, c = _realCheck(line, pattern:gsub('$VALUE', QVALREPL))
220		if k ~= nil then
221			return k,v, c
222		end
223		return _realCheck(line, pattern:gsub('$VALUE', WORDREPL))
224	else
225		return _realCheck(line, pattern)
226	end
227end
228
229-- str in this table is a regex pattern.  It will automatically be anchored to
230-- the beginning of a line and any preceding whitespace will be skipped.  The
231-- pattern should have no more than two captures patterns, which correspond to
232-- the two parameters (usually 'key' and 'value') that are passed to the
233-- process function.  All trailing characters will be validated.  Any $VALUE
234-- token included in a pattern will be tried first with a quoted value capture
235-- group, then a single-word value capture group.  This is our kludge for Lua
236-- regex not supporting branching.
237--
238-- We have two special entries in this table: the first is the first entry,
239-- a full-line comment.  The second is for 'exec' handling.  Both have a single
240-- capture group, but the difference is that the full-line comment pattern will
241-- match the entire line.  This does not run afoul of the later end of line
242-- validation that we'll do after a match.  However, the 'exec' pattern will.
243-- We document the exceptions with a special 'groups' index that indicates
244-- the number of capture groups, if not two.  We'll use this later to do
245-- validation on the proper entry.
246--
247local pattern_table = {
248	{
249		luaexempt = true,
250		str = "(#.*)",
251		process = function(_, _)  end,
252		groups = 1,
253	},
254	--  module_load="value"
255	{
256		name = MODULEEXPR .. "_load%s*",
257		val = "%s*$VALUE",
258		process = function(k, v)
259			if modules[k] == nil then
260				modules[k] = {}
261			end
262			modules[k].load = v:upper()
263			setEnv(k .. "_load", v:upper())
264		end,
265	},
266	--  module_name="value"
267	{
268		name = MODULEEXPR .. "_name%s*",
269		val = "%s*$VALUE",
270		process = function(k, v)
271			setKey(k, "name", v)
272			setEnv(k .. "_name", v)
273		end,
274	},
275	--  module_type="value"
276	{
277		name = MODULEEXPR .. "_type%s*",
278		val = "%s*$VALUE",
279		process = function(k, v)
280			setKey(k, "type", v)
281			setEnv(k .. "_type", v)
282		end,
283	},
284	--  module_flags="value"
285	{
286		name = MODULEEXPR .. "_flags%s*",
287		val = "%s*$VALUE",
288		process = function(k, v)
289			setKey(k, "flags", v)
290			setEnv(k .. "_flags", v)
291		end,
292	},
293	--  module_before="value"
294	{
295		name = MODULEEXPR .. "_before%s*",
296		val = "%s*$VALUE",
297		process = function(k, v)
298			setKey(k, "before", v)
299			setEnv(k .. "_before", v)
300		end,
301	},
302	--  module_after="value"
303	{
304		name = MODULEEXPR .. "_after%s*",
305		val = "%s*$VALUE",
306		process = function(k, v)
307			setKey(k, "after", v)
308			setEnv(k .. "_after", v)
309		end,
310	},
311	--  module_error="value"
312	{
313		name = MODULEEXPR .. "_error%s*",
314		val = "%s*$VALUE",
315		process = function(k, v)
316			setKey(k, "error", v)
317			setEnv(k .. "_error", v)
318		end,
319	},
320	--  exec="command"
321	{
322		luaexempt = true,
323		name = "exec%s*",
324		val = "%s*" .. QVALEXPR,
325		process = function(k, _)
326			if cli_execute_unparsed(k) ~= 0 then
327				print(MSG_FAILEXEC:format(k))
328			end
329		end,
330		groups = 1,
331	},
332	--  env_var="value" or env_var=[word|num]
333	{
334		name = "([%w][%w%d-_.]*)%s*",
335		val = "%s*$VALUE",
336		process = function(k, v)
337			local pv, msg = processEnvVar(v)
338			if not pv then
339				print(MSG_FAILPARSEVAR:format(k, msg))
340				return
341			end
342			if setEnv(k, pv) ~= 0 then
343				print(MSG_FAILSETENV:format(k, v))
344			else
345				return pv
346			end
347		end,
348	},
349}
350
351local function isValidComment(line)
352	if line ~= nil then
353		local s = line:match("^%s*#.*")
354		if s == nil then
355			s = line:match("^%s*$")
356		end
357		if s == nil then
358			return false
359		end
360	end
361	return true
362end
363
364local function getBlacklist()
365	local blacklist = {}
366	local blacklist_str = loader.getenv('module_blacklist')
367	if blacklist_str == nil then
368		return blacklist
369	end
370
371	for mod in blacklist_str:gmatch("[;, ]?([-%w_]+)[;, ]?") do
372		blacklist[mod] = true
373	end
374	return blacklist
375end
376
377local function loadModule(mod, silent)
378	local status = true
379	local blacklist = getBlacklist()
380	local pstatus
381	for k, v in pairs(mod) do
382		if v.load ~= nil and v.load:lower() == "yes" then
383			local module_name = v.name or k
384			if not v.force and blacklist[module_name] ~= nil then
385				if not silent then
386					print(MSG_MODBLACKLIST:format(module_name))
387				end
388				goto continue
389			end
390			if not silent then
391				loader.printc(module_name .. "...")
392			end
393			local str = "load "
394			if v.type ~= nil then
395				str = str .. "-t " .. v.type .. " "
396			end
397			str = str .. module_name
398			if v.flags ~= nil then
399				str = str .. " " .. v.flags
400			end
401			if v.before ~= nil then
402				pstatus = cli_execute_unparsed(v.before) == 0
403				if not pstatus and not silent then
404					print(MSG_FAILEXBEF:format(v.before, k))
405				end
406				status = status and pstatus
407			end
408
409			if cli_execute_unparsed(str) ~= 0 then
410				print(loader.command_error())
411				if not silent then
412					print("failed!")
413				end
414				if v.error ~= nil then
415					cli_execute_unparsed(v.error)
416				end
417				status = false
418			elseif v.after ~= nil then
419				pstatus = cli_execute_unparsed(v.after) == 0
420				if not pstatus and not silent then
421					print(MSG_FAILEXAF:format(v.after, k))
422				end
423				if not silent then
424					print("ok")
425				end
426				status = status and pstatus
427			end
428		end
429		::continue::
430	end
431
432	return status
433end
434
435local function readFile(name, silent)
436	local f = io.open(name)
437	if f == nil then
438		if not silent then
439			print(MSG_FAILOPENCFG:format(name))
440		end
441		return nil
442	end
443
444	local text, _ = io.read(f)
445	-- We might have read in the whole file, this won't be needed any more.
446	io.close(f)
447
448	if text == nil and not silent then
449		print(MSG_FAILREADCFG:format(name))
450	end
451	return text
452end
453
454local function checkNextboot()
455	local nextboot_file = loader.getenv("nextboot_conf")
456	local nextboot_enable = loader.getenv("nextboot_enable")
457
458	if nextboot_file == nil then
459		return
460	end
461
462	-- is nextboot_enable set in nvstore?
463	if nextboot_enable == "NO" then
464		return
465	end
466
467	local text = readFile(nextboot_file, true)
468	if text == nil then
469		return
470	end
471
472	if nextboot_enable == nil and
473	    text:match("^nextboot_enable=\"NO\"") ~= nil then
474		-- We're done; nextboot is not enabled
475		return
476	end
477
478	if not config.parse(text) then
479		print(MSG_FAILPARSECFG:format(nextboot_file))
480	end
481
482	-- Attempt to rewrite the first line and only the first line of the
483	-- nextboot_file. We overwrite it with nextboot_enable="NO", then
484	-- check for that on load.
485	-- It's worth noting that this won't work on every filesystem, so we
486	-- won't do anything notable if we have any errors in this process.
487	local nfile = io.open(nextboot_file, 'w')
488	if nfile ~= nil then
489		-- We need the trailing space here to account for the extra
490		-- character taken up by the string nextboot_enable="YES"
491		-- Or new end quotation mark lands on the S, and we want to
492		-- rewrite the entirety of the first line.
493		io.write(nfile, "nextboot_enable=\"NO\" ")
494		io.close(nfile)
495	end
496	loader.setenv("nextboot_enable", "NO")
497end
498
499local function processEnv(k, v)
500	for _, val in ipairs(pattern_table) do
501		if not val.luaexempt and val.name then
502			local matched = k:match(val.name)
503
504			if matched then
505				return val.process(matched, v)
506			end
507		end
508	end
509end
510
511-- Module exports
512config.verbose = false
513
514-- The first item in every carousel is always the default item.
515function config.getCarouselIndex(id)
516	return carousel_choices[id] or 1
517end
518
519function config.setCarouselIndex(id, idx)
520	carousel_choices[id] = idx
521end
522
523-- Returns true if we processed the file successfully, false if we did not.
524-- If 'silent' is true, being unable to read the file is not considered a
525-- failure.
526function config.processFile(name, silent)
527	if silent == nil then
528		silent = false
529	end
530
531	local text = readFile(name, silent)
532	if text == nil then
533		return silent
534	end
535
536	if name:match(".lua$") then
537		local cfg_env = setmetatable({}, {
538			indices = {},
539			__index = function(env, key)
540				if getmetatable(env).indices[key] then
541					return rawget(env, key)
542				end
543
544				return loader.getenv(key)
545			end,
546			__newindex = function(env, key, val)
547				getmetatable(env).indices[key] = true
548				rawset(env, key, val)
549			end,
550		})
551
552		-- Give local modules a chance to populate the config
553		-- environment.
554		hook.runAll("config.buildenv", cfg_env)
555		local res, err = pcall(load(text, name, "t", cfg_env))
556		if res then
557			for k, v in pairs(cfg_env) do
558				local t = type(v)
559				if t ~= "function" and t ~= "table" then
560					if t ~= "string" then
561						v = tostring(v)
562					end
563					local pval = processEnv(k, v)
564					if pval then
565						setEnv(k, pval)
566					end
567				end
568			end
569		else
570			print(MSG_FAILEXECLUA:format(name, err))
571		end
572
573		return res
574	else
575		return config.parse(text)
576	end
577end
578
579-- silent runs will not return false if we fail to open the file
580function config.parse(text)
581	local n = 1
582	local status = true
583
584	for line in text:gmatch("([^\n]+)") do
585		if line:match("^%s*$") == nil then
586			for _, val in ipairs(pattern_table) do
587				if val.str == nil then
588					val.str = val.name .. "=" .. val.val
589				end
590				local pattern = '^%s*' .. val.str .. '%s*(.*)';
591				local cgroups = val.groups or 2
592				local k, v, c = checkPattern(line, pattern)
593				if k ~= nil then
594					-- Offset by one, drats
595					if cgroups == 1 then
596						c = v
597						v = nil
598					end
599
600					if isValidComment(c) then
601						val.process(k, v)
602						goto nextline
603					end
604
605					break
606				end
607			end
608
609			print(MSG_MALFORMED:format(n, line))
610			status = false
611		end
612		::nextline::
613		n = n + 1
614	end
615
616	return status
617end
618
619function config.readConf(file, loaded_files)
620	if loaded_files == nil then
621		loaded_files = {}
622	end
623
624	if loaded_files[file] ~= nil then
625		return
626	end
627
628	local top_level = next(loaded_files) == nil -- Are we the top-level readConf?
629	print("Loading " .. file)
630
631	-- The final value of loader_conf_files is not important, so just
632	-- clobber it here.  We'll later check if it's no longer nil and process
633	-- the new value for files to read.
634	setEnv("loader_conf_files", nil)
635
636	-- These may or may not exist, and that's ok. Do a
637	-- silent parse so that we complain on parse errors but
638	-- not for them simply not existing.
639	if not config.processFile(file, true) then
640		print(MSG_FAILPARSECFG:format(file))
641	end
642
643	loaded_files[file] = true
644
645	-- Going to process "loader_conf_files" extra-files
646	local loader_conf_files = getEnv("loader_conf_files")
647	if loader_conf_files ~= nil then
648		for name in loader_conf_files:gmatch("[%w%p]+") do
649			config.readConf(name, loaded_files)
650		end
651	end
652
653	if top_level then
654		local loader_conf_dirs = getEnv("loader_conf_dirs")
655
656		-- If product_vars is set, it must be a list of environment variable names
657		-- to walk through to guess product information. The order matters as
658		-- reading a config files override the previously defined values.
659		--
660		-- If product information can be guessed, for each product information
661		-- found, also read config files found in /boot/loader.conf.d/PRODUCT/.
662		local product_vars = getEnv("product_vars")
663		if product_vars then
664			local product_conf_dirs = ""
665			for var in product_vars:gmatch("%S+") do
666				local product = getEnv(var)
667				if product then
668					product_conf_dirs = product_conf_dirs .. " /boot/loader.conf.d/" .. product
669				end
670			end
671
672			if loader_conf_dirs then
673				loader_conf_dirs = loader_conf_dirs .. product_conf_dirs
674			else
675				loader_conf_dirs = product_conf_dirs
676			end
677		end
678
679		-- Process "loader_conf_dirs" extra-directories
680		if loader_conf_dirs ~= nil then
681			for name in loader_conf_dirs:gmatch("[%w%p]+") do
682				if lfs.attributes(name, "mode") ~= "directory" then
683					print(MSG_FAILDIR:format(name))
684					goto nextdir
685				end
686
687				for cfile in lfs.dir(name) do
688					if cfile:match(".conf$") then
689						local fpath = name .. "/" .. cfile
690						if lfs.attributes(fpath, "mode") == "file" then
691							config.readConf(fpath, loaded_files)
692						end
693					end
694				end
695				::nextdir::
696			end
697		end
698
699		-- Always allow overriding with local config files, e.g.,
700		-- /boot/loader.conf.local.
701		local local_loader_conf_files = getEnv("local_loader_conf_files")
702		if local_loader_conf_files then
703			for name in local_loader_conf_files:gmatch("[%w%p]+") do
704				config.readConf(name, loaded_files)
705			end
706		end
707	end
708end
709
710-- other_kernel is optionally the name of a kernel to load, if not the default
711-- or autoloaded default from the module_path
712function config.loadKernel(other_kernel)
713	local flags = loader.getenv("kernel_options") or ""
714	local kernel = other_kernel or loader.getenv("kernel")
715
716	local function tryLoad(names)
717		for name in names:gmatch("([^;]+)%s*;?") do
718			local r = loader.perform("load " .. name ..
719			     " " .. flags)
720			if r == 0 then
721				return name
722			end
723		end
724		return nil
725	end
726
727	local function getModulePath()
728		local module_path = loader.getenv("module_path")
729		local kernel_path = loader.getenv("kernel_path")
730
731		if kernel_path == nil then
732			return module_path
733		end
734
735		-- Strip the loaded kernel path from module_path. This currently assumes
736		-- that the kernel path will be prepended to the module_path when it's
737		-- found.
738		kernel_path = escapeName(kernel_path .. ';')
739		return module_path:gsub(kernel_path, '')
740	end
741
742	local function loadBootfile()
743		local bootfile = loader.getenv("bootfile")
744
745		-- append default kernel name
746		if bootfile == nil then
747			bootfile = "kernel"
748		else
749			bootfile = bootfile .. ";kernel"
750		end
751
752		return tryLoad(bootfile)
753	end
754
755	-- kernel not set, try load from default module_path
756	if kernel == nil then
757		local res = loadBootfile()
758
759		if res ~= nil then
760			-- Default kernel is loaded
761			config.kernel_loaded = nil
762			return true
763		else
764			print(MSG_DEFAULTKERNFAIL)
765			return false
766		end
767	else
768		-- Use our cached module_path, so we don't end up with multiple
769		-- automatically added kernel paths to our final module_path
770		local module_path = getModulePath()
771		local res
772
773		if other_kernel ~= nil then
774			kernel = other_kernel
775		end
776		-- first try load kernel with module_path = /boot/${kernel}
777		-- then try load with module_path=${kernel}
778		local paths = {"/boot/" .. kernel, kernel}
779
780		for _, v in pairs(paths) do
781			loader.setenv("module_path", v)
782			res = loadBootfile()
783
784			-- succeeded, add path to module_path
785			if res ~= nil then
786				config.kernel_loaded = kernel
787				if module_path ~= nil then
788					loader.setenv("module_path", v .. ";" ..
789					    module_path)
790					loader.setenv("kernel_path", v)
791				end
792				return true
793			end
794		end
795
796		-- failed to load with ${kernel} as a directory
797		-- try as a file
798		res = tryLoad(kernel)
799		if res ~= nil then
800			config.kernel_loaded = kernel
801			return true
802		else
803			print(MSG_KERNFAIL:format(kernel))
804			return false
805		end
806	end
807end
808
809function config.selectKernel(kernel)
810	config.kernel_selected = kernel
811end
812
813function config.load(file, reloading)
814	if not file then
815		file = "/boot/defaults/loader.conf"
816	end
817
818	config.readConf(file)
819
820	checkNextboot()
821
822	local verbose = loader.getenv("verbose_loading") or "no"
823	config.verbose = verbose:lower() == "yes"
824	if not reloading then
825		hook.runAll("config.loaded")
826	end
827end
828
829-- Reload configuration
830function config.reload(file)
831	modules = {}
832	restoreEnv()
833	config.load(file, true)
834	hook.runAll("config.reloaded")
835end
836
837function config.loadelf()
838	local xen_kernel = loader.getenv('xen_kernel')
839	local kernel = config.kernel_selected or config.kernel_loaded
840	local status
841
842	if xen_kernel ~= nil then
843		print(MSG_XENKERNLOADING)
844		if cli_execute_unparsed('load ' .. xen_kernel) ~= 0 then
845			print(MSG_XENKERNFAIL:format(xen_kernel))
846			return false
847		end
848	end
849	print(MSG_KERNLOADING)
850	if not config.loadKernel(kernel) then
851		return false
852	end
853	hook.runAll("kernel.loaded")
854
855	print(MSG_MODLOADING)
856	status = loadModule(modules, not config.verbose)
857	hook.runAll("modules.loaded")
858	return status
859end
860
861function config.enableModule(modname)
862	if modules[modname] == nil then
863		modules[modname] = {}
864	elseif modules[modname].load == "YES" then
865		modules[modname].force = true
866		return true
867	end
868
869	modules[modname].load = "YES"
870	modules[modname].force = true
871	return true
872end
873
874function config.disableModule(modname)
875	if modules[modname] == nil then
876		return false
877	elseif modules[modname].load ~= "YES" then
878		return true
879	end
880
881	modules[modname].load = "NO"
882	modules[modname].force = nil
883	return true
884end
885
886function config.isModuleEnabled(modname)
887	local mod = modules[modname]
888	if not mod or mod.load ~= "YES" then
889		return false
890	end
891
892	if mod.force then
893		return true
894	end
895
896	local blacklist = getBlacklist()
897	return not blacklist[modname]
898end
899
900function config.getModuleInfo()
901	return {
902		modules = modules,
903		blacklist = getBlacklist()
904	}
905end
906
907hook.registerType("config.buildenv")
908hook.registerType("config.loaded")
909hook.registerType("config.reloaded")
910hook.registerType("kernel.loaded")
911hook.registerType("modules.loaded")
912return config
913